Unable to Open Project after HLODS Build's Fail (Building/Deleting HLODS makes Project CRASH)

General Issues and Bug Reporting
, ,
1

Summary

I’ve had problems building the HLODS on this island since the beginning: every time I tried to build them, I got a Fail error with a pop-up. I found a solution: changing the Cell Size and Loading Range of both the HLODS and the island’s Main Partition, allowing me to build them at least once (it didn’t work with multiple builds).

I recently tried building them again using the temporary fix listed above, but the UEFN editor crashed. I tried opening it again without success, and now it won’t open anymore. It always crashes at around 72%, while ‘‘uploading plugins’’. I’ll give the relative HLODS fail’s log and Crash log in the comments.

Please select what you are reporting on:

Unreal Editor for Fortnite

What Type of Bug are you experiencing?

Assets

Steps to Reproduce

  • Try to build HLODS

Expected Result

HLODs should build successfully

Observed Result

I Always receive bunch of warnings and errors in the Output Log after trying or in some cases successfully build the HLODS. Now I’m unable to open the project after a crash due to HLODS build’s fail.

Platform(s)

PC

2

HLODS FAIL:

WorldPartitionHLODsBuilder-00004544-2026-01-27T12.18.14.407Z.rar (98.4 KB)

CRASH:

UnrealEditorFortnite.rar (111.3 KB)

3

hi @Majorrblues ,

The log before the crash says

[2026.01.27-13.53.31:076][926]LogAssetRegistry: Error: Package is unloadable: C:/Users/oibaf/Documents/Fortnite Projects/trying/Content/ExternalActors/trying/5/W2/B781WPOXYARM192MNVYO98.uasset.

Reason: Invalid value for PACKAGE_FILE_TAG at start of file.

Try putting B781WPOXYARM192MNVYO98 search box of the Asset box to find the asset then delete this

The alternative is Win File explorer and find the asset above and delete the asset

The probable cause is the dimensions are not the power of two

Document Resizing Textures contains error 512 is not a Power Of 2 - General / Issues and Bug Reporting - Epic Developer Community Forums

4

Hello,

I tried to delete the file in the Project’s folder (since I can’t access the project from the editor) with no luck, still crashes at 72% while Loading Plugins.

5

hi @Majorrblues ,

Please verify your installation just in case something in UEFN is corrupted

How to verify UEFN

6

Tried to verify and also make a fresh install of both Fortnite and UEFN, still doesn’t work

7

image
image1885×402 126 KB

I managed to open it randomly, I think its just luck, and these errors are the errors im receiving now that I always used to have when launching the project and also after the HLODS Fail.

Now I can’t launch sessions since it gives me Validation Error with just one .uasset file (which I found refers to the HLODS). I don’t know what to do since I don’t wan’t to close the editor because I might not be able to open the project again.

Last time I tried to delete the HLODS from the ‘‘Build’’ Tool up in the Editor it just crashed. I need to find a way to delete HLODS safely somehow

8

hi @Majorrblues

The only answer that may be of use is

VALIDATION FAIL on build HLOD packages. - General / Issues and Bug Reporting - Epic Developer Community Forums

Updated for 5.5

World Partition - Hierarchical Level of Detail in Unreal Engine | Unreal Engine 5.5 Documentation | Epic Developer Community

9

Well, I managed to fix it by deleting some asset files that were causing errors and made a new Default HLOD Layer. I also removed Unreal Revision Control, which prevented me from building HLODS in any other project. I probably had some luck, but thanks for the advices. Hopefully now it won’t crash again while building them…

1 Like
10

Why would Unreal Revision Control prevent you from building HLODS in other projects? What errors do you get?